M7350/filesystems/mtd-utils/compr.c

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2024-09-09 08:57:42 +00:00
/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
* University of Szeged, Hungary
*
* For licensing information, see the file 'LICENCE' in this directory
* in the jffs2 directory.
*/
#include "compr.h"
#include <string.h>
#include <stdlib.h>
#include <linux/jffs2.h>
#define FAVOUR_LZO_PERCENT 80
extern int page_size;
/* LIST IMPLEMENTATION (from linux/list.h) */
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
__list_add(new, head->prev, head);
}
static inline void __list_del(struct list_head *prev, struct list_head *next)
{
next->prev = prev;
prev->next = next;
}
static inline void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = (void *) 0;
entry->prev = (void *) 0;
}
#define list_entry(ptr, type, member) \
((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
#define list_for_each_entry(pos, head, member) \
for (pos = list_entry((head)->next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.next, typeof(*pos), member))
/* Available compressors are on this list */
static LIST_HEAD(jffs2_compressor_list);
/* Actual compression mode */
static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
void jffs2_set_compression_mode(int mode)
{
jffs2_compression_mode = mode;
}
int jffs2_get_compression_mode(void)
{
return jffs2_compression_mode;
}
/* Statistics for blocks stored without compression */
static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
/* Compression test stuffs */
static int jffs2_compression_check = 0;
static unsigned char *jffs2_compression_check_buf = NULL;
void jffs2_compression_check_set(int yesno)
{
jffs2_compression_check = yesno;
}
int jffs2_compression_check_get(void)
{
return jffs2_compression_check;
}
static int jffs2_error_cnt = 0;
int jffs2_compression_check_errorcnt_get(void)
{
return jffs2_error_cnt;
}
#define JFFS2_BUFFER_FILL 0x55
/* Called before compression (if compression_check is setted) to prepare
the buffer for buffer overflow test */
static void jffs2_decompression_test_prepare(unsigned char *buf, int size)
{
memset(buf,JFFS2_BUFFER_FILL,size+1);
}
/* Called after compression (if compression_check is setted) to test the result */
static void jffs2_decompression_test(struct jffs2_compressor *compr,
unsigned char *data_in, unsigned char *output_buf,
uint32_t cdatalen, uint32_t datalen, uint32_t buf_size)
{
uint32_t i;
/* buffer overflow test */
for (i=buf_size;i>cdatalen;i--) {
if (output_buf[i]!=JFFS2_BUFFER_FILL) {
fprintf(stderr,"COMPR_ERROR: buffer overflow at %s. "
"(bs=%d csize=%d b[%d]=%d)\n", compr->name,
buf_size, cdatalen, i, (int)(output_buf[i]));
jffs2_error_cnt++;
return;
}
}
/* allocing temporary buffer for decompression */
if (!jffs2_compression_check_buf) {
jffs2_compression_check_buf = malloc(page_size);
if (!jffs2_compression_check_buf) {
fprintf(stderr,"No memory for buffer allocation. Compression check disabled.\n");
jffs2_compression_check = 0;
return;
}
}
/* decompressing */
if (!compr->decompress) {
fprintf(stderr,"JFFS2 compression check: there is no decompress function at %s.\n", compr->name);
jffs2_error_cnt++;
return;
}
if (compr->decompress(output_buf,jffs2_compression_check_buf,cdatalen,datalen)) {
fprintf(stderr,"JFFS2 compression check: decompression failed at %s.\n", compr->name);
jffs2_error_cnt++;
}
/* validate decompression */
else {
for (i=0;i<datalen;i++) {
if (data_in[i]!=jffs2_compression_check_buf[i]) {
fprintf(stderr,"JFFS2 compression check: data mismatch at %s (pos %d).\n", compr->name, i);
jffs2_error_cnt++;
break;
}
}
}
}
/*
* Return 1 to use this compression
*/
static int jffs2_is_best_compression(struct jffs2_compressor *this,
struct jffs2_compressor *best, uint32_t size, uint32_t bestsize)
{
switch (jffs2_compression_mode) {
case JFFS2_COMPR_MODE_SIZE:
if (bestsize > size)
return 1;
return 0;
case JFFS2_COMPR_MODE_FAVOURLZO:
if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > size))
return 1;
if ((best->compr != JFFS2_COMPR_LZO) && (bestsize > size))
return 1;
if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > (size * FAVOUR_LZO_PERCENT / 100)))
return 1;
if ((bestsize * FAVOUR_LZO_PERCENT / 100) > size)
return 1;
return 0;
}
/* Shouldn't happen */
return 0;
}
/* jffs2_compress:
* @data: Pointer to uncompressed data
* @cdata: Pointer to returned pointer to buffer for compressed data
* @datalen: On entry, holds the amount of data available for compression.
* On exit, expected to hold the amount of data actually compressed.
* @cdatalen: On entry, holds the amount of space available for compressed
* data. On exit, expected to hold the actual size of the compressed
* data.
*
* Returns: Lower byte to be stored with data indicating compression type used.
* Zero is used to show that the data could not be compressed - the
* compressed version was actually larger than the original.
* Upper byte will be used later. (soon)
*
* If the cdata buffer isn't large enough to hold all the uncompressed data,
* jffs2_compress should compress as much as will fit, and should set
* *datalen accordingly to show the amount of data which were compressed.
*/
uint16_t jffs2_compress( unsigned char *data_in, unsigned char **cpage_out,
uint32_t *datalen, uint32_t *cdatalen)
{
int ret = JFFS2_COMPR_NONE;
int compr_ret;
struct jffs2_compressor *this, *best=NULL;
unsigned char *output_buf = NULL, *tmp_buf;
uint32_t orig_slen, orig_dlen;
uint32_t best_slen=0, best_dlen=0;
switch (jffs2_compression_mode) {
case JFFS2_COMPR_MODE_NONE:
break;
case JFFS2_COMPR_MODE_PRIORITY:
orig_slen = *datalen;
orig_dlen = *cdatalen;
output_buf = malloc(orig_dlen+jffs2_compression_check);
if (!output_buf) {
fprintf(stderr,"mkfs.jffs2: No memory for compressor allocation. Compression failed.\n");
goto out;
}
list_for_each_entry(this, &jffs2_compressor_list, list) {
/* Skip decompress-only backwards-compatibility and disabled modules */
if ((!this->compress)||(this->disabled))
continue;
this->usecount++;
if (jffs2_compression_check) /*preparing output buffer for testing buffer overflow */
jffs2_decompression_test_prepare(output_buf, orig_dlen);
*datalen = orig_slen;
*cdatalen = orig_dlen;
compr_ret = this->compress(data_in, output_buf, datalen, cdatalen);
this->usecount--;
if (!compr_ret) {
ret = this->compr;
this->stat_compr_blocks++;
this->stat_compr_orig_size += *datalen;
this->stat_compr_new_size += *cdatalen;
if (jffs2_compression_check)
jffs2_decompression_test(this, data_in, output_buf, *cdatalen, *datalen, orig_dlen);
break;
}
}
if (ret == JFFS2_COMPR_NONE) free(output_buf);
break;
case JFFS2_COMPR_MODE_FAVOURLZO:
case JFFS2_COMPR_MODE_SIZE:
orig_slen = *datalen;
orig_dlen = *cdatalen;
list_for_each_entry(this, &jffs2_compressor_list, list) {
uint32_t needed_buf_size;
if (jffs2_compression_mode == JFFS2_COMPR_MODE_FAVOURLZO)
needed_buf_size = orig_slen + jffs2_compression_check;
else
needed_buf_size = orig_dlen + jffs2_compression_check;
/* Skip decompress-only backwards-compatibility and disabled modules */
if ((!this->compress)||(this->disabled))
continue;
/* Allocating memory for output buffer if necessary */
if ((this->compr_buf_size < needed_buf_size) && (this->compr_buf)) {
free(this->compr_buf);
this->compr_buf_size=0;
this->compr_buf=NULL;
}
if (!this->compr_buf) {
tmp_buf = malloc(needed_buf_size);
if (!tmp_buf) {
fprintf(stderr,"mkfs.jffs2: No memory for compressor allocation. (%d bytes)\n",orig_dlen);
continue;
}
else {
this->compr_buf = tmp_buf;
this->compr_buf_size = orig_dlen;
}
}
this->usecount++;
if (jffs2_compression_check) /*preparing output buffer for testing buffer overflow */
jffs2_decompression_test_prepare(this->compr_buf,this->compr_buf_size);
*datalen = orig_slen;
*cdatalen = orig_dlen;
compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen);
this->usecount--;
if (!compr_ret) {
if (jffs2_compression_check)
jffs2_decompression_test(this, data_in, this->compr_buf, *cdatalen, *datalen, this->compr_buf_size);
if (((!best_dlen) || jffs2_is_best_compression(this, best, *cdatalen, best_dlen))
&& (*cdatalen < *datalen)) {
best_dlen = *cdatalen;
best_slen = *datalen;
best = this;
}
}
}
if (best_dlen) {
*cdatalen = best_dlen;
*datalen = best_slen;
output_buf = best->compr_buf;
best->compr_buf = NULL;
best->compr_buf_size = 0;
best->stat_compr_blocks++;
best->stat_compr_orig_size += best_slen;
best->stat_compr_new_size += best_dlen;
ret = best->compr;
}
break;
default:
fprintf(stderr,"mkfs.jffs2: unknown compression mode.\n");
}
out:
if (ret == JFFS2_COMPR_NONE) {
*cpage_out = data_in;
*datalen = *cdatalen;
none_stat_compr_blocks++;
none_stat_compr_size += *datalen;
}
else {
*cpage_out = output_buf;
}
return ret;
}
int jffs2_register_compressor(struct jffs2_compressor *comp)
{
struct jffs2_compressor *this;
if (!comp->name) {
fprintf(stderr,"NULL compressor name at registering JFFS2 compressor. Failed.\n");
return -1;
}
comp->compr_buf_size=0;
comp->compr_buf=NULL;
comp->usecount=0;
comp->stat_compr_orig_size=0;
comp->stat_compr_new_size=0;
comp->stat_compr_blocks=0;
comp->stat_decompr_blocks=0;
list_for_each_entry(this, &jffs2_compressor_list, list) {
if (this->priority < comp->priority) {
list_add(&comp->list, this->list.prev);
goto out;
}
}
list_add_tail(&comp->list, &jffs2_compressor_list);
out:
return 0;
}
int jffs2_unregister_compressor(struct jffs2_compressor *comp)
{
if (comp->usecount) {
fprintf(stderr,"mkfs.jffs2: Compressor modul is in use. Unregister failed.\n");
return -1;
}
list_del(&comp->list);
return 0;
}
#define JFFS2_STAT_BUF_SIZE 16000
char *jffs2_list_compressors(void)
{
struct jffs2_compressor *this;
char *buf, *act_buf;
act_buf = buf = malloc(JFFS2_STAT_BUF_SIZE);
list_for_each_entry(this, &jffs2_compressor_list, list) {
act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority);
if ((this->disabled)||(!this->compress))
act_buf += sprintf(act_buf,"disabled");
else
act_buf += sprintf(act_buf,"enabled");
act_buf += sprintf(act_buf,"\n");
}
return buf;
}
char *jffs2_stats(void)
{
struct jffs2_compressor *this;
char *buf, *act_buf;
act_buf = buf = malloc(JFFS2_STAT_BUF_SIZE);
act_buf += sprintf(act_buf,"Compression mode: ");
switch (jffs2_compression_mode) {
case JFFS2_COMPR_MODE_NONE:
act_buf += sprintf(act_buf,"none");
break;
case JFFS2_COMPR_MODE_PRIORITY:
act_buf += sprintf(act_buf,"priority");
break;
case JFFS2_COMPR_MODE_SIZE:
act_buf += sprintf(act_buf,"size");
break;
case JFFS2_COMPR_MODE_FAVOURLZO:
act_buf += sprintf(act_buf, "favourlzo");
break;
default:
act_buf += sprintf(act_buf, "unknown");
break;
}
act_buf += sprintf(act_buf,"\nCompressors:\n");
act_buf += sprintf(act_buf,"%10s ","none");
act_buf += sprintf(act_buf,"compr: %d blocks (%d) decompr: %d blocks\n", none_stat_compr_blocks,
none_stat_compr_size, none_stat_decompr_blocks);
list_for_each_entry(this, &jffs2_compressor_list, list) {
act_buf += sprintf(act_buf,"%10s (prio:%d) ",this->name,this->priority);
if ((this->disabled)||(!this->compress))
act_buf += sprintf(act_buf,"- ");
else
act_buf += sprintf(act_buf,"+ ");
act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d) decompr: %d blocks ", this->stat_compr_blocks,
this->stat_compr_new_size, this->stat_compr_orig_size,
this->stat_decompr_blocks);
act_buf += sprintf(act_buf,"\n");
}
return buf;
}
int jffs2_set_compression_mode_name(const char *name)
{
if (!strcmp("none",name)) {
jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
return 0;
}
if (!strcmp("priority",name)) {
jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
return 0;
}
if (!strcmp("size",name)) {
jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
return 0;
}
if (!strcmp("favourlzo", name)) {
jffs2_compression_mode = JFFS2_COMPR_MODE_FAVOURLZO;
return 0;
}
return 1;
}
static int jffs2_compressor_Xable(const char *name, int disabled)
{
struct jffs2_compressor *this;
list_for_each_entry(this, &jffs2_compressor_list, list) {
if (!strcmp(this->name, name)) {
this->disabled = disabled;
return 0;
}
}
return 1;
}
int jffs2_enable_compressor_name(const char *name)
{
return jffs2_compressor_Xable(name, 0);
}
int jffs2_disable_compressor_name(const char *name)
{
return jffs2_compressor_Xable(name, 1);
}
int jffs2_set_compressor_priority(const char *name, int priority)
{
struct jffs2_compressor *this,*comp;
list_for_each_entry(this, &jffs2_compressor_list, list) {
if (!strcmp(this->name, name)) {
this->priority = priority;
comp = this;
goto reinsert;
}
}
fprintf(stderr,"mkfs.jffs2: compressor %s not found.\n",name);
return 1;
reinsert:
/* list is sorted in the order of priority, so if
we change it we have to reinsert it into the
good place */
list_del(&comp->list);
list_for_each_entry(this, &jffs2_compressor_list, list) {
if (this->priority < comp->priority) {
list_add(&comp->list, this->list.prev);
return 0;
}
}
list_add_tail(&comp->list, &jffs2_compressor_list);
return 0;
}
int jffs2_compressors_init(void)
{
#ifdef CONFIG_JFFS2_ZLIB
jffs2_zlib_init();
#endif
#ifdef CONFIG_JFFS2_RTIME
jffs2_rtime_init();
#endif
#ifdef CONFIG_JFFS2_LZO
jffs2_lzo_init();
#endif
return 0;
}
int jffs2_compressors_exit(void)
{
#ifdef CONFIG_JFFS2_RTIME
jffs2_rtime_exit();
#endif
#ifdef CONFIG_JFFS2_ZLIB
jffs2_zlib_exit();
#endif
#ifdef CONFIG_JFFS2_LZO
jffs2_lzo_exit();
#endif
return 0;
}